The Tech Tour stacks are locked to prevent accidental changing of the
information contained in the stacks. We are not trying to prevent the
information in the stacks from being used. To unlock the stack, hold down
the Command key while pulling down the "File" menu. Select the "Protect
Stack..." menu option. Click on the check box next to the phrase "Can't
Modify Stack" and then set the user level to "Scripting". This makes it
possible to edit the stack as normal.